Adaptive Reallocation Research Articles

Securing the Environmental Water Requirements of Seasonally Ponding Wetlands: Partnering Science and Management through Benefit Sharing

Although environmental flow regime assessments are becoming increasingly holistic, they rarely provoke water managers to enact the adaptive water reallocation mechanisms required to secure environmental water for wetlands. The conditions that cause science-based environmental flow assessments to succeed or fail in informing the management of environmental water requirements remain unclear. To begin to resolve these conditions, we used process tracing to deconstruct the sequence of activities required to manage environmental water in four case studies of seasonally ponding wetlands in Mediterranean and Mesoamerican watersheds. We hypothesized that, when the flexibility and equitability of the socioeconomic system do not match the complexity of the biophysical system, this leads to a failure of managers to integrate scientific guidance in their allocation of environmental water. Diagnostic evidence gathered indicates that science-management partnerships are essential to align institutional flexibility and socioeconomic equitability with the system’s ecohydrological complexity, and thus move from determination to reallocation of environmental water. These results confirm that institutions e.g., river basin organizations need to be supplemented by motivated actors with experience and skill to negotiate allocation and adaptive management of environmental water. These institutional-actor synergies are likely to be especially important in water scarce regions when the need to accommodate extreme hydrological conditions is not met by national governance capacity. We conclude by focusing on benefit sharing as a means to better describe the conditions for successful science-based environmental flow assessments that realize productive efficiency in environmental water allocation i.e., recognition of multiple values for both people and ecosystems.

Dietary restriction and lifespan: adaptive reallocation or somatic sacrifice?

Reducing overall food intake, or lowering the proportion of protein relative to other macronutrients, can extend the lifespan of diverse organisms. A number of mechanistic theories have been developed to explain this phenomenon, mostly assuming that the molecules connecting diet to lifespan are evolutionarily conserved. A recent study using Drosophila melanogaster females has pinpointed a single essential micronutrient that can explain how lifespan is changed by dietary restriction. Here, we propose a likely mechanism for this observation, which involves a trade-off between lifespan and reproduction, but in a manner that is conditional on the dietary supply of an essential micronutrient - a sterol. Importantly, these observations argue against previous evolutionary theories that rely on constitutive resource reallocation or damage directly inflicted by reproduction. Instead, they are compatible with a model in which the inverse relationship between lifespan and food level is caused by the consumer suffering from varying degrees of malnutrition when maintained on lab food. The data also indicate that animals on different lab foods may suffer from different nutritional imbalances and that the mechanisms by which dietary restriction benefits the lifespan of different species may vary. This means that translating the mechanistic findings from lab animals to humans will not be simple and should be interpreted in light of the range of challenges that have shaped each organism's lifespan in the wild and the composition of the natural diets upon which they would feed.

A Perspective on Social-Ecological System Framework And New Institutional Economics Theories in Explaining Public Open Spaces (Pos) Governance And Quality Issues

There has been relatively little attention paid to the implications of property-rights structures on urban and neighbourhood commons, particularly in respect to government/state-owned public open space (POS) governance, its management and its quality. By establishing interconnections of the property-rights structure with POS governance and its quality externalities, the theory of new institutional economics, the social-ecological system framework, as well as the social dilemma theory and the commons and opportunism concepts were employed and reviewed, to synthesise a conceptual framework which can help illuminate and explain the complex nexus of an institutional-social-POS system. Findings suggested that adversarial institutional design and arrangement (e.g., maladaptive property regime, incomplete rights, and attenuated rights) and change of the property-rights system, coupled with highly positive transaction cost distributions, contribute to inefficient POS governance and management, which consequently results in a suboptimal quality and sustainability of POS. This synthesis provides policy and management insights by making public officials aware of the importance of the institutional-social-ecological system, and by making them consider a re-engineering of the POS ownership regime and its management rights via an adaptive property-rights structure assessment and re-allocation.

Shifting landscapes: decoupled urban irrigation and greenness patterns during severe drought

Urban outdoor water conservation and efficiency offer high potential for demand-side management, but irrigation, greenness, and climate interlinks must be better understood to design optimal policies. To identify paired transitions during drought, we matched parcel-level water use data from smart, dedicated irrigation meters with high-spatial resolution, multispectral aerial imagery. We examined changes across 72 non-residential parcels using potable or recycled water for large landscape irrigation over four biennial summers (2010, 2012, 2014, and 2016) that encompassed a historic drought in California. We found that despite little change in irrigation levels during the first few years of the drought, parcel greenness deteriorated. Between summers 2010 and 2014, average parcel greenness decreased −61% for potable water irrigators and −56% for recycled water irrigators, providing evidence that vegetation could not reach its vigor from wetter, cooler years as the drought intensified with abnormally high temperatures. Between summers 2014–2016 as drought severity lessened, irrigation rates decreased significantly in line with high drought saliency, but greenness rebounded ubiquitously, on average +110% for potable water irrigators and +62% for recycled water irrigators, demonstrating climate-driven vegetation recovery as evaporation and plant evapotranspiration rates decreased. Transitions were similar for customers with both potable and recycled water; vegetation changes were dominated by the overarching climatic regime. As irrigation cannot always overcome drought conditions, which will become more severe under climate change, to maintain vegetation health, utilities and urban planners should consider the tradeoffs between providing green spaces and water scarcity. This includes evaluating the roles of climate-appropriate landscaping and adaptive reallocation of potable and recycled water resources to enhance water security. By addressing emerging themes in urban water management through analysis of data from forthcoming water metering and aerial imagery technologies, this research provides a unique perspective on water use, greenness, and drought linkages.

An Energy-Quality Utility-Based Adaptive Scheduling Solution for Mobile Users in Dense Networks

There is an important trend in terms of user expectations of ubiquity in relation to rich media services and increase in number and range of devices with high specifications which enable access to such services, with very ambitious technical requirements. Providing this support is a very challenging issue, especially in urban dense network environments (DenseNet). Diverse solutions have been proposed, including deployment of femtocells in conjunction with the existing infrastructure, but there is still need for new approaches to balance resources and quality in current competitive market. This paper proposes an innovative three-phase adaptive scheduling solution [energy-quality utility-based adaptive scheduling solution (EQUAS)], which performs trade off between service quality and energy efficiency when allocating network resources to mobile users in a DenseNet. Resource allocation is performed according to a utility function that takes into account throughput, device energy consumption, and user mobility. Furthermore, adaptive reallocation is applied to increase network coverage and avoid dropping service. Testing results show how EQUAS outperforms two competitive approaches in terms of energy consumption and efficiency, data throughput, and estimated user satisfaction.

Adaptive reallocation of cybersecurity analysts to sensors for balancing risk between sensors

Cyber Security Operations Center (CSOC) is a service-oriented system. Analysts work in shifts, and the goal at the end of each shift is to ensure that all alerts from each sensor (client) are analyzed. The goal is often not met because the CSOC is faced with adverse conditions such as variations in alert generation rates or in the time taken to thoroughly analyze new alerts. Current practice at many CSOCs is to pre-assign analysts to sensors based on their expertise, and the alerts from the sensors are triaged, queued, and presented to analysts. Under adverse conditions, some sensors have more number of unanalyzed alerts (backlogs) than others, which results in a major security gap for the clients if left unattended. Hence, there is a need to dynamically reallocate analysts to sensors; however, there does not exist a mechanism to ensure the following objectives: (i) balancing the number of unanalyzed alerts among sensors while maximizing the number of alerts investigated by optimally reallocating analysts to sensors in a shift, (ii) ensuring desirable properties of the CSOC: minimizing the disruption to the analyst to sensor allocation made at the beginning of the shift when analysts report to work, balancing of workload among analysts, and maximizing analyst utilization. The paper presents a technical solution to achieve the objectives and answers two important research questions: (i) detection of triggers, which determines when-to reallocate, and (ii) how to optimally reallocate analysts to sensors, which enable a CSOC manager to effectively use reallocation as a decision-making tool.

A Neurocomputational Account of How Inflammation Enhances Sensitivity to Punishments Versus Rewards

BackgroundInflammation rapidly impairs mood and cognition and, when severe, can appear indistinguishable from major depression. These sickness responses are characterized by an acute reorientation of motivational state; pleasurable activities are avoided, and sensitivity to negative stimuli is enhanced. However, it remains unclear how these rapid shifts in behavior are mediated within the brain. MethodsHere, we combined computational modeling of choice behavior, experimentally induced inflammation, and functional brain imaging (functional magnetic resonance imaging) to describe these mechanisms. Using a double-blind, randomized crossover study design, 24 healthy volunteers completed a probabilistic instrumental learning task on two separate occasions, one 3 hours after typhoid vaccination and one 3 hours after saline (placebo) injection. Participants learned to select high probability reward (win £1) and avoid high probability punishment (lose £1) stimuli. An action-value learning algorithm was fit to the observed behavior, then used within functional magnetic resonance imaging analyses to identify neural coding of prediction error signals driving motivational learning. ResultsInflammation acutely biased behavior, enhancing punishment compared with reward sensitivity, through distinct actions on neural representations of reward and punishment prediction errors within the ventral striatum and anterior insula. Consequently, choice options leading to potential rewards were less behaviorally attractive, and those leading to punishments were more aversive. ConclusionsOur findings demonstrate the neural mediation of a rapid, state-dependent reorientation of reward versus punishment sensitivity during inflammation. This mechanism may aid the adaptive reallocation of metabolic resources during acute sickness but might also account for maladaptive, motivational changes that underpin the association between chronic inflammation and depression.

Economy of vision and adaptive reallocation of neural resources

Economy of vision and adaptive reallocation of neural resources

Effects of food restriction across stages of juvenile and early adult development on body weight, survival and adult life history.

Organisms have to allocate limited resources among multiple life-history traits, which can result in physiological trade-offs, and variation in environmental conditions experienced during ontogeny can influence reproduction later in life. Food restriction may lead to an adaptive reallocation of the limited resources among traits as a phenotypically plastic adjustment, or it can act as an overall constraint with detrimental effects throughout reproductive life. In this study, we investigated experimentally the effects of food restriction during different stages of the juvenile and early adult development on body weight, survival and reproductive success in females and males of the European earwig Forficula auricularia. Individuals either received limited or unlimited access to food across three different stages of development (fully crossed) allowing us to identify sensitive periods during development and to test both additive and interactive effects of food limitation across stages on development and reproduction. Food restriction during the early and late juvenile stage had additive negative effects on juvenile survival and adult body weight. With regard to reproductive success of females which produce up to two clutches in their lifetime, restriction specifically in the late juvenile stage led to smaller first and second clutch size, lower probability of second clutch production and reduced hatching success in the second clutch. Reproductive success of females was not significantly affected when their male mates experienced food restriction during their development. Our findings in general support the 'silver-spoon' hypothesis in that food restriction during juvenile development poses constraints on development and reproduction throughout life.

Dynamic adaptive changes of the serum carnitine esters during and after L-carnitine supplementation in patients with maintenance haemodialysis

Background. Here we report the serum carnitine ester profile during and after 1g iv/day L-carnitine supplementation in haemodialysis patients. Materials and methods. Seven patients were studied over 29 weeks. After a control day, 12 weeks of replacement therapy was introduced followed by 17 weeks of washout period. The serum acylcarnitine concentrations were determined by isotope dilution ESI MS/MS technique. Results. At baseline significantly decreased free carnitine (48%, p < 0.01) and a 1.5–16-fold elevation of 16 out of 27 acylcarnitines were detected in HD patients compared with the controls. On the last day of L-carnitine supplementation a 1.6–4.8-fold increase was observed in the acylcarnitine levels compared with day 0; the increase-profile was achieved in four different patterns. The increase rate was rapid and early saturable for C5, C5OH, C6DC, C8:1, C10DC and C18:2 esters, slower for C2, C4, C6, C18 and C18:1 esters, it was slowest and reached a late plateau for C3, C8DC, C14:2, C16 and C16:1, and finally almost gradual increase was seen for 11 acylcarnitines. Three months after the cessation of carnitine treatment marked concentration drops were found for almost all acylcarnitines (by 11–74 % of week 12, p < 0.05); the values further decreased over the five remaining weeks of the observation period. Conclusion. Carnitine administration affected the levels of circulating esters in different dynamics and kinetics suggesting a regulated, non-random adaptive reallocation of nutrients. A considerable washout was achieved 3 months after discontinuation of the supplementation; however, the profile still was suggestive for presence of rest of accumulated supplement.

Is ALARP applicable to the management of terrorist risks?

In this paper, we discuss the applicability of the as low as reasonable practicable (ALARP) principle to terrorist risk management. ALARP is a commonly used framework for managing risk due to non-intelligent threats, but terrorism introduces difficult issues, both technically and socially. In particular, the probability of a terrorist attack is difficult to define, terrorist threats are adaptive, and some terrorist risk management actions raise issues of loss of civil liberties not raised by risk management measures for other types of risk. We discuss these issues and their implications for risk management. After showing how ALARP is used to manage the risk from other hazards in different economic sectors, we discuss both the benefits and difficulties associated with extending the ALARP framework for terrorist risk analysis. We conclude that the ALARP framework can be modified to make it appropriate for risk management for adaptive risks, provided that care is taken to explicitly consider adaptive reallocation of risk in response to risk management actions, to account for perceived or actual loss of civil liberties resulting from risk management actions, and to consider the difficulties associated with using probability to measure uncertainty in adversary actions.

Amino-acid imbalance explains extension of lifespan by dietary restriction in Drosophila

Dietary restriction (DR) extends healthy lifespan in diverse organisms, and reduces fecundity 1,2. DR is widely assumed to induce adaptive reallocation of nutrients from reproduction to somatic maintenance, aiding survival of food shortages in nature 3-6. Long life under DR and high fecundity under full feeding would thus be mutually exclusive, through competition for the same, limiting nutrients. We tested this idea, by identifying the nutrients producing the responses of lifespan and fecundity to DR in Drosophila. Adding essential amino acids to a DR diet increased fecundity and decreased lifespan, similar to full feeding, with other nutrients having little or no effect. However, methionine alone increased fecundity as much as full feeding, but without reducing lifespan. Reallocation of nutrients therefore does not explain the DR responses. Lifespan was reduced by amino acids, particularly essential amino acids. Hence an imbalance in dietary amino acids away from the ratio optimal for reproduction shortens lifespan during full feeding and limits fecundity during DR. Reduced activity of the insulin/Igf signaling pathway extends lifespan in diverse organisms 7, and it protected against the shortening of lifespan with full feeding. In other organisms, including mammals, it may be possible to obtain the benefits for lifespan of DR without reduced fecundity, through a suitable balance of nutrients in the diet.

A note on contrafreeloading in broilers compared to layer chicks

Contrafreeloading (CFL) is the behaviour where an animal chooses to work for food even when identical food can be obtained without any effort. Previous studies have suggested that the difference in CFL between White Leghorn layers and jungle fowl may be a side effect of selection for increased production traits in the Leghorn strain. In this experiment we studied to what extent broilers chicks (Cobb/Ross), which are highly selected for fast growth, perform CFL and compared this with a layer strain (Calder Ranger), which grows considerably slower. We predicted that broilers should have a lower degree of CFL compared to the layer strain, as an energy-saving response to the demands of rapid growth. During 48 h 10 pairs of each breed were given a choice between freely available food and food mixed with wood shavings. Behavioural observations were made twice each day. Broilers showed less CFL ( p < 0.05), were more inactive ( p < 0.001) and performed less active behaviours ( p < 0.05) than layers. Our results support previous findings that decreased CFL in domestic fowl may indicate adaptive reallocation of energy resources in response to selection for increased production traits.

A Comparison of Performance Criteria for Initiating Adaptive Task Reallocation

This study examined performance assessment methods used to initiate mode transfers between manual control and automation for adaptive task reallocation. Participants monitored two secondary displays for critical events while actively controlling a process in a fictional system. One of the secondary tasks could be automated whenever participant performance surpassed absolute threshold values or after evidence of a continued change in performance beyond the threshold criteria. Transfers were either machine-initiated or human-initiated after the computer signaled the participant to change modes. First, the results support previous findings (Montgomery, 2001). In addition, it appears that by including the human operator in machine-initiated transfers the proportion of mode errors (i.e., accidental responses while a task is automated) may be reduced relative to transfers that are completely machine-initiated with the operator being simply informed of the current mode. Secondly, the results indicated that the assessment method that required a change in performance produced performance advantages, including evidence of a decrease in the proportion of mode errors, relative to the absolute threshold criteria without a heavy reliance on automation.

Reproductive effort decreases antibody responsiveness

The prevalence and intensity of parasitic infection often increases in animals when they are reproducing. This may be a consequence of increased rates of parasite transmission due to reproductive effort. Alternatively, endocrine changes associated with reproduction can lead to immunosuppression. Here we provide support for a third potential mechanism: reduced immunocompetence as a consequence of adaptive reallocation of resources in times of increased energetic demand. In captive zebra finches Taeniopygia guttata, reproductive effort was manipulated through brood size. Enhanced effort was found to affect the production of antibodies towards sheep red blood cells. In addition, activity of zebra finches was manipulated independently of parental care. Experimentally increased daily workloads in activity reward schedules also suppressed antibody production. Thus, we show that not just the reproductive state, but the increased activity that accompanies reproduction is associated with immunocompetence. This mechanism may be sufficient to explain the increased parasitism observed in reproducing animals. We suggest that reduced immunocompetence as a consequence of increased reproductive effort may be an important pathway for the life history cost of reproduction.

Natural Selection, the Costs of Reproduction, and a Refinement of Lack's Principle

Natural Selection, the Costs of Reproduction, and a Refinement of Lack's Principle